1. Field of the Invention
The present invention relates to a network management method for performing desired communication among data processing apparatuses in a network wherein a plurality of data processing apparatuses, for example, computers, are connected, an apparatus for the same, and a network system which can adequately perform such communication.
2. Description of the Related Art
Along with the development of data processing technology and communication technology, progress has been made in the construction of a network in which various data processing apparatuses are connected and information is used and various data processings are performed more effectively.
For example, progress has been made in the construction of an internetwork creating a large scale network by connecting a plurality of computer networks. Particularly, the so-called xe2x80x9cInternetxe2x80x9d, which is a global scale network using TCP/IP as a protocol, may be typical example of such a network.
In the Internet, an IP address and domain name are given to each node on the network. An IP address is an identification number of each data processing apparatus connected to the network and represented by 32 bits of integer. Further, a domain name is a name which enables differentiation of a node on the network by a symbolic name having meaning to the user and is given to each range of management of a network divided into such ranges. These IP address and domain name must not be duplicated on the network, that is, throughout the world, and are centrally managed by a network information center (NIC).
When performing communication with a desired node in such a space, a point-to-point physical connection is made via a router or the like.
Further, in recent years, cable television (CATV) systems have been rapidly growing. Video-on-demand (VOD) and other services provided in such CATV systems are services which are provided in an environment where two-way communication is possible. Such an allotter network now has a strong color as an information network.
Further, networks of various formats and various sizes are rapidly spreading such as with the construction of digital exchange networks and ISDN, the spread of mobile communication networks, and the start of satellite communication services.
In the networks mentioned before, however, there was the problem that there were numerous restrictions on the configuration or processing systems based on physical conditions, so it was very difficult to effectively realize various processings via the network.
First, all of such networks have a central centralized management system, thus must set the spatial information of the network in advance. For this reason, flexibility with respect to the configuration of the network is poor and, in addition, if the size of the network becomes large, there arises a problem that the management costs of the network space thereof becomes large.
More specifically, in for example the Internet as mentioned before, the IP addresses and the domain names are managed by the NIC. Therefore, when it is intended to newly add a data processing apparatus, a local network, or the like to the network, application must be made to the NIT for granting of the same, thus a node cannot be immediately and arbitrarily added.
On the other hand, demand for mobile computing has rapidly increased in recent years. There are now strong demands that the nodes be able to be dynamically added to the network.
Further, there was a demand that, together with flexibility with respect to the configuration of each network, the processing with respect to that network be able to be easily carried out by for example the logic name set by the application or the logical network configuration. Further, there has been a demand that high grade network processing such as, for example, the placement of a program module on each node on the network and the network wide distributed processing, be performed, but the current network management method could not answer such a demand.
Further, as mentioned before, irrespective of the spread of networks of various formats, usually connection is only possible by one route of one format. Comprehensive network utilization could not be achieved. For example, even when the Internet and the cable TV network are connected, they are merely connected in series and cannot be effectively utilized.
An object of the present invention is to provide a network management method that increases the flexibility in configuration or processing system for networks of various formats and thereby makes the connection relationship among the networks closer so as to enable more effective data processing on the network, in other words, more effective service.
Another object of the present invention is to provide a network management apparatus for realizing such a network.
Another object of the present invention is meant to provide such a network system.
In order to solve the above-mentioned problems, the network is managed for each local partial network. Along with this, the communication among the nodes is performed by propagation of a space search by hypothetical connections.
Accordingly, the network management method of the present invention has a connection request having at least a logical node name of the destination of connection successively propagated to a node having a possibility of active connection with the node of the destination of connection based on information on nodes in the vicinity of that node stored in each node; has a route for actively connecting desired nodes is searched for; and has the nodes made to actively connect and communication between the nodes made to be performed.
Preferably, the information of nodes in a partial network and the information of another partial network connected to the partial network are managed for each of any partial networks of the network; and based on the information managed in each partial network, in each partial network, the connection request is propagated to another partial network having a possibility of active connection with the node of the destination of connection and a node having a possibility of active connection with the node of the destination of connection in the partial network so as to search for the route.
More preferably, a node is added or deleted by updating only the information managed by the partial network containing the node to be added or deleted.
Still more preferably, between networks having different formats, the node to which the networks having the different formats are connected manages the format and information of both of the different networks, converts the format of the connection request, and propagates the connection request.
Specifically, when a plurality of nodes are retrieved as destinations of connection by the search, a single optimum node is selected from among the retrieved plurality of nodes by a predetermined evaluation method and the selected node is actively connected to the node of the origin of request and made to perform the communication. Any evaluation method can be adopted as this evaluation method. For example, it is also possible to set data that indicates the attributes of the node in the connection request and compare the data with the attributes of the retrieved node to perform the evaluation and it is also possible to use the distance of the route as the evaluation value and select the node with the shortest route.
Specifically, when a plurality of routes are retrieved among the nodes by the search, any plurality of routes among the plurality of routes are made actively valid and the communication is performed in parallel via the plurality of routes. For example, where a route via a cable TV network and a route via a public telephone line are retrieved, it is also possible to transmit video data via the cable TV network and transmit audio data via the public telephone line. Further, it is also possible to perform the transmission of the AV data via the cable TV network and transmit the charge information with respect to the transmitted AV data via the public telephone line.
Further, conversely to the case mentioned before, when a plurality of routes are retrieved among the nodes by the search, it is also possible to select a single optimum route from among the retrieved plurality of routes by a predetermined evaluation method and actively connect the nodes by the selected route to perform the communication. This evaluation can be carried out by a similar method to the evaluation of the nodes. Further, particularly in the case of the selection of the route, preferably the route is selected according to the type of the transmission data. For example, where a cable TV network and public telephone line are retrieved, it is sufficient so far as the cable TV network is selected if the AV data is to be transmitted, while the public telephone line is selected if audio data and text data are selected.
Further, specifically, in the data management method of the present invention, the route between the retrieved desired nodes is secured as the communication route, that is, the connection of lines is maintained, and the communication is carried out between those nodes by this.
Further, specifically, any transmission data is given to the connection request and propagated and the data transfer between desired nodes is carried out by this. Namely, even if the lines are not always connected, it is sufficient so far as a state of connection is temporarily establish during only the period where the connection request of for example the packet format is transferred.
In such a case, particularly where this transmission data is the control data at the node of the destination of connection, the destination of connection can be made to perform the predetermined processing by transferring only the connection request by such a search. Namely, the predetermined processing with respect to any node can be controlled, and the control of the program modules among nodes and parallel processing by a plurality of nodes can be managed.
Further, where this transmission data is the data for requesting the acquisition of information, predetermined information can be requested from the destination of connection by just transferring the connection request by such a search and, further, the information as the result of this can be obtained via the route obtained at that search.
Further, preferably, in the network management method of the present invention, by managing the program module processed at each node connected to the network in the same way as the nodes, a connection request regarding a program module as the destination of connection requested by a node or a program module is successively propagated to a node having a possibility of active connection with the program module of the destination of connection based on the information on the nodes in the vicinity of the node and program module, which is stored in each node; the route which can be actively connected to the program module of the destination of connection is searched for; and the node or program module of the origin of request and the program module of the destination of connection are actively connected by the route and made to perform the communication.
Further, in the network management apparatus of the present invention is provided for every optional partial network of the network to which a plurality of nodes are connected; manages the information of the nodes in the partial network and the other partial network connected to this partial network; and outputs a connection request having at least the logical node name of the destination of connection which is input via the network to another partial network having a possibility of active connection with the node of the destination of connection and the node having a possibility of active connection with the node of the destination of connection in this partial network based on the management information.
Preferably, in the network management apparatus, at least the information of the nodes in the partial network is updated based on the information of addition or deletion of nodes in the partial network which was input.
Further, another network management apparatus of the present invention is provided among a plurality of networks having different formats; manages the format and information of two of the networks having different formats; converts in format a connection request having at least the logical node name of the destination of connection input from any network; outputs the same to another network to propagate the connection request among different networks; and thereby searches for the connection route between the desired nodes.
Preferably, the network management apparatus updates the information of the network based on the information of addition or deletion of the nodes of the plurality of networks which was input.
Further, in the network system of the present invention, a plurality of nodes, each of which manages information of the nodes in the vicinity thereof and outputs a connection request having at least the logical node name of the destination of connection input via the network to a node having a possibility of active connection with the node of the destination of connection based on the information managed in the node, are connected on the network; the route connecting the desired nodes is searched for by propagating the connection request; and the nodes are actively connected and the communication between the nodes is carried out. Note that the size of this network system is not relevant in any way. For example, the invention can be applied as also a distributed processing system used in a closed environment such as a business and can be applied as a global wide area network.
Preferably, the network system further has a partial network managing means for managing the information of nodes in the partial network and the information of another partial network connected to the partial network for each of any partial networks of the network and outputting a connection request to another partial network having a possibility of active connection with the node of the destination of connection and the node having a possibility of active connection with the node of the destination of connection in the partial network based on the managed information.
Preferably, in the network system, at the time of addition or deletion of a node, only the information of the node stored in the partial network managing means of the partial network containing the node to be added or deleted is updated and a state enabling communication is maintained between any nodes.
Preferably, in the network system, the network is constituted by a plurality of networks having different formats and provision is further made of a router means which is provided among the plurality of networks having different formats, manages the format and information of two of the networks having different formats, converts the format of the connection request input from any network, and outputs the same to another network.
Preferably, when a plurality of nodes are retrieved as the destination of connection by the search, a single optimum node is selected from among the retrieved plurality of nodes by a predetermined evaluation method and the selected node is actively connected to the node of the origin of request to perform the communication.
Specifically, when a plurality of routes are retrieved among the nodes by the search, the nodes are actively connected by any plurality of routes among the plurality of routes to perform the communication.
Also, specifically, when a plurality of routes are retrieved among the nodes by the search, a single optimum route is selected from among the retrieved plurality of routes by a predetermined evaluation method and the nodes are actively connected by the selected route to perform the communication.
Further, specifically, in the network system of the present invention, the route through which the connection request between the desired nodes is propagated is secured as a communication route to perform communication between the desired nodes.
Preferably, the connection request further has any control data and a predetermined processing based on the control data is carried out at the node of the destination of connection by establishing the active connection.
Also, preferably, the connection request further has data for requesting the acquisition of any information and the information based on the data for requesting the acquisition is transferred from the node of the destination of connection to the node of the origin of request via the route through which the connection request is propagated by establishing the active connection.
Further, in the network system of the present invention, each of the nodes manages the information of the program modules processed at the nodes in the vicinity thereof or the node and outputs a connection request regarding the input program module as the destination of connection to a node having a possibility of active connection with the program module as the destination of connection based on the information of the nodes and program modules in the vicinity thereof; the connection request is propagated; the route which enables active connection to the program module of the destination of connection is searched for; and the node or the program module of the origin of request and the program module of the destination of connection are actively connected by the route to perform the communication.